Sunday, July 1, 2012

Image 1: The small amounts of sodium-alginate, aka E401 many chocolates and commercially produced foods contain is obviously not enough to ward off obesity. Otherwise the obesity rates should have fallen not risen with the increase in crappy foods.

Aside from the ubiquitous stimulant based fatburners there is another class of weight loss supplements emerging as of late. Those of you who have read Adelfo's Thursday post, here at the SuppVersity, may have seen his plug for Myotropics' WM-HDP based "new Fat Burning Carbohydrate" ThermiCarb(TM). Now as hilarious as it may sound, this resistant starch is in fact as much of a "fat burner" as any of the 1001 currently available stims is. After all, none of those products actively burns fat. What still makes them effective, though, is their ability to shift substrate utilization away from glucose and towards fat, to curb appetite and to deliver the energy you need to do what it takes to shed body fat, i.e. to function normally while eating slightly less and working out.

Contrary to the good old (and certainly not obsolete) stims, these new "fat burners" act on the gut-brain axis, instead of HPA (the hypothalamus-pituatary-adrenal axis), by stimulating the release of a whole host of peptides from the gut. Among those, the incretin hormones GLP-1 & co. (cf. "Eat More, Burn More and Lose Fat Like on Crack with GLP-1!?") are probably the best understood among these mis-understood "satiety hormones" with their profound downstream effects on overall energy expenditure, glucose and fatty acid metabolism (Mudaliar. 2012).

Is alginate, a polysaccharide from marine brown algae, a novel "fat burning fiber"?

Next to designer-starches such as WM-HDP there is also an increasing interest in the effects natural fiber / fiber extracts, such as the 15g alginate from brown algae the obese subjects (0–55y; BMI 30-45kg/m²) in a recent study from the University of Copenhagen in Denmark had to consume before each of their three meals in the course of a 12-week double-blind randomized parallel-intervention (Jenson. 2012), exert on the endocrine signals from your gut.

Image 2: Popsticles are not the only products containing sodium alginate (E401) as a thickener and stabilizer. If you take a closer look at the ingredients of the stuff in the supermarkets, you will notice that many commercially produced low fat dairy products, ready made sauces, gravies, dressings, puddings, pies and pastry fillings contain it, as well.

What is alginate? Alginate is a gelling polysaccharide (gelling = it forms a gel which passes slowly through your digestive tract) that is extracted from marine brown algae. In seaweed the mannuronic and guluronic acid based components are responsible for the mechanical strength and flexibility. During the regular extraction process alginate is bound to sodium. The result, sodium alginate, has been used a E401 in various foodstuffs to stabilize, gel or viscosify it for years now (Brownlee. 2005). The appetite reducing effects of sodium alginate and other marine-derived fiber are widely known, but the underlying mechanism is still not completely elucidated. According to the current paradigm, it is related to the interaction of sodium-alginate and calcium during the digestive process and the subsequent changes in viscosity of the gastric content, which has been associated with slowed gastric emptying and a reduction of postprandial glucose and insulin response. Of these the latter, i.e. the prolonged influx of glucose, the absence of blood glucose spikes and the overall reduction in insulin levels is currently believed to be at the heart of the observed satiety effects (Cani. 2009).

What is interesting about this study is that according to the self-set goals of the scientists, which lay at the ground of their "Intention-To-Treat analysis" (ITT), which evaluated the changes in body weight and overall body composition, as well as the improvements of metabolic risk factors as a whole, yielded no differences between the two study arms.

Figure 1: Changes in body weight and body composition in response to caloric reduction (-300kcal/day) with or without supplemental alginate (15g/day) after 12 weeks (large graph); actual weight development over the whole 12-week study period (small graph; directly from Jenson. 2012)

If you do yet take a closer look at the actual study data (see figure 1), you will see that there were very important differences between those dieters who simply consumed 300kcal/per day less (control group) and those who followed the exact same calorically reduced dietary regimen yet with an additional 15g of fiber from sodium alginate before every meal (alginate group)!

Lose more weight, more fat and do this at a constant rate beyond week 9!

Despite the fact that onlye the differences between the reduction in total weight and body fat percentage reached statistical significance, this and the absence of the "weight loss plateau" in week 9+ (see figure 1, right) in the alginate group clearly suggest that much contrary to what Jenson et al. had apprehended, the previously demonstrated short-term weight loss benefits of fibrous algae extract and other dietary fiber (Paxman. 2008; Odunsi. 2010; Peters. 2011; Wanders. 2011) did not disappear after an initial adaptation phase. On the contrary! The 40% greater reduction in body weight, as well as the 36% greater reduction in body fat percentage would be of little value if the body weight stagnated after only -6.78kg weight loss in week 9 and left the dieters with an average BMI of 32kg/m² well in the obesity / danger zone.

Figure 2: Changes in glucose metabolism and ghrelin (left) and lipid metabolism (right) in response to caloric reduction (-300kcal/day) with or without
supplemental alginate (15g/day) after 12 weeks (large graph); actual
weight development over the whole 12-week study period (small graph;
directly from Jenson. 2012)

Looking back at the exact weight development in figure 1 (right), we may thus speculate that the observed improvements of the measured markers of blood glucose management and lipid metabolism of which only the HbA1c (not shown in figure 2) showed a statistically significant inter-group difference (+0.01% in control -0.01% in alginate; p < 0.024) would have reached statistical significance after 16-20 weeks. This is particularly true for the insulin levels, for which the difference between control and alginate group is already borderline significant (p < 0.062) after 12 weeks of alginate supported dieting.

As usual we do however have to remember that the subjects in this study were more than just a little chubby, with body fat percentages in the >40% range a reduction of -5.8% (control) and -8.2% (alginate) is easier achieved than a (from a merely mathematical standpoint) equal -12% of the body fat content from 12% to 10%. So, while healthy dieters don't have to care about the minimal, but statistically significantly lower reduction in blood pressure in response to weight loss with sodium-alginate (the scientists ascribe this to the relatively high sodium content of the alginate supplement), the will probably not benefit in the same way as Jenson's obese subjects from the additional 45g of fiber per day. Well, unless, it exerts similar effects effects as they have been observed for hydroxypropyl-distarches (cf. "Waxy Maize Reloaded") on the expression of GIP, GLP-1 and the whole host of the initially mentioned incretin hormones, and adipokines (Sánchez. 2012) and don't just curb appetite and slow digestion.

If it had all those GBA (gut brain axis ;-) effects, seaweed derived sodium-alginate supplements could however make an ideal adjunct to a ~20% reduction in food intake, a reasonable fat loss workout (e.g. "Step By Step Guide to Your Own Workout Routine - Part V: Example Routines - Round 2: Fat Loss Support Routine") and a stimulant-based fat burner of your choice, whenever you strive to cut a few pounds of body weight. I mean, just imagine if Duong (see image 3), who likewise dieted for 12 weeks would have lost 35% more fat mass - yeah you're right, he would probably have been "disgustingly" lean, as Adelfo likes to call it ;-)

Additional Ressources

Join the Newsletter

Disclaimer:

The information provided on this website is for informational purposes only. It is by no means intended as professional medical advice. Do not use any of the agents or freely available dietary supplements mentioned on this website without further consultation with your medical practitioner.